1. Field of the Invention
The invention relates to a method of driving light sources, a light source driving device for performing the method, and a display apparatus having the light source driving device. More particularly, the invention relates to a method of driving light sources by generating a local dimming signal for individually driving a plurality of dimming blocks, a light source driving device for performing the method, and a display apparatus having the light source driving device.
2. Description of the Related Art
In general, a liquid crystal display (LCD) device displays an image using a liquid crystal that has optical characteristics such as anisotropy of refractivity and electrical characteristics such as anisotropy of dielectric constant. LCD devices have various advantages such as thinner thickness, lower driving voltage, lower power consumption, etc., compared to other display devices such as cathode ray tube (CRT) devices and plasma display panel (PDP) devices. Therefore, LCD devices are used in laptop computers, monitors, television receiver sets, mobile phones, etc. LCD devices display image using optical and electrical properties of liquid crystal molecules, such as anisotropic refractive index and anisotropic dielectric constant. LCD devices include an LCD panel displaying an image using optical transmittance of liquid crystal molecules and a backlight assembly providing light to the LCD panel.
An LCD panel includes a first substrate having a plurality of pixel electrodes arranged in a matrix shape, a second substrate opposite to the first substrate with common electrode formed thereon, and a liquid crystal layer interposed between the first substrate and the second substrate.
A backlight assembly employs a plurality of cathode fluorescent lamps (CCFLs) as light sources. Recently, a plurality of light-emitting diodes (LEDs) having low power consumption and high color reproducibility has been employed as the backlight assembly.
A backlight assembly may generate light by individually driving dimming blocks arranged in a matrix shape to increase contrast ratio and to decrease power consumption. In such a device, the backlight assembly includes a dimming logic element for individually controlling the LEDs in each dimming blocks.
Generally, the size and the number of the dimming blocks may be determined according to the resolution of the LCD panel; the dimming logic element individually controls the dimming blocks according to the size or the number of the dimming blocks that is optimized to the resolution of the LCD panel.
However, when the resolution of the LCD panel is altered for various models, the dimming logic element may be required to be replaced with another dimming logic element that is optimized to the altered resolution, increasing cost of production.